1. Field of Endeavor
The present invention relates to the detection and treatment of chemical and biological agents, and more particularly, to a system for protecting a building or other enclosed airspace from harmful aerosol particles.
2. State of Technology
Biological agent weapons have been around at least since the Middle Ages when soldiers are reported to have catapulted the bodies of dead smallpox or plague victims over fortress walls in the hope of infecting their enemies or at least demoralizing them. Today, biological weapons (BW) are appearing in the news with increasing frequency. The anthrax threat in Las Vegas in February 1998 is an example. Surplus stores in Las Vegas sold out of gas masks, and talk-radio shows were swamped with callers asking about evacuation points. That threat turned out to be a false alarm, but the next one might be real. The Aum Shinrikyo cult grew and released anthrax spores in Tokyo, but, fortunately they did not have and effective means of dispersal of the spores and no deaths were reported. In Sverdlovisk, Union of Soviet Socialistic Republics in 1979 a quantity of dry anthrax spores were accidentally released from a military facility, killing 67 people downwind.
Biological agents are of concern in part because of the ease with which many of them can be manufactured, transported, and dispensed. Because of the lag time between a biological attack and the appearance of symptoms in those exposed, biological weapons could be devastating. Many biological agents are contagious; and during this lag time, infected persons could continue to spread the disease, further increasing its reach. Hundreds or even thousands of people could become sick or die if a biological attack were to occur in a major metropolitan area.
A historical example illustrates the scale of the effort required to respond to an act of BW terror in a major metropolitan area. In 1947, an American businessman traveled to New York City from Mexico City. During his bus ride, he developed a fever, headache, and rash. Though ill upon his arrival in New York, he went sightseeing. Over a period of several hours, he walked around the city and through a major department store. His illness, smallpox, progressed and he died nine days later. As a result of this single case, other cases of smallpox and two deaths occurred. Because of smallpox""s ability to be transmitted from person to person, this handful of cases was deemed so serious by public health officials that 6,350,000 persons in New York City alone were vaccinated in less than a month.
In view of the foregoing, there is an increasing need for a system for detecting and eliminating biological and chemical agents. The system could be installed in a building or other area with an enclosed airspace. For example the system could be installed in subways, airports, entertainment centers, religious centers, office complexes, convention centers, and other sites where the public is at high risk of exposure to a covert release of biological or chemical agents. The system could also be part of a network of systems installed in urban areas or large events such as inaugurations or the Olympics.
The majority of detection and identification systems that are currently commercially available generally require a laboratory setting for testing and are designed for one positive detection only (Military System). There is also the question xe2x80x9cwhat would be recommended as an action, if a real pathogen were detected?xe2x80x9d Most people do not have a HEPA-filtered mask available. Even if a HEPA-filtered mask were available, it would likely not be properly fitted; and the individual would likely not be properly trained for its use.
The present invention provides a prophylactic approach that can avoid many of the problems of the prior art by providing monitoring and remediation of the entire air supply. The prior art systems are piecemeal systems that do not provide an entire solution to the problem. For example, the system described in The World Intellectual Property Organization International Patent Application No. WO 98/58743 to Patricia Irving and Donald Hammerstrom, assigned to Coma Catalysis Corporation and Battelle Memorial Institute, filed Jun. 16, 1998, an electrostatic precipitator capable of separating Am size particulate matter for a gaseous stream is described. Alternating plates and ground collector plates are placed in a particulate laden gas stream. The collector plates are provided with a plurality of micro-machined channels therein aligned generally perpendicular to the flow of gas through the device. The channels are provided with a liquid flowing therethrough to collect and concentrate the particulates collected therein. Analytical means may be provided to analyze the particulate matter thus collected.
U.S. Pat. No. 4,140,005 to David B. Kittelson, assigned to The Regents of the University of Minnesota, filed Feb. 20, 1979, and issued Mar. 22, 1977, describes a method and instrument for continuous monitoring of an aerosol as the sulfur content of atmospheric aerosols. The instrument has an electrostatic precipitator that is turned off and on at a given frequency to modulate the particle concentration of aerosol flowing through the precipitator. A total sulfur flame photometric detector sensitive to both gaseous and particulate sulfur receives a sample of the modulated aerosol from the precipitator. The modulated particle concentration of the aerosol supplied to the detector causes a fluctuating component in the detector output that is directly related to the sulfur particle concentration. This component is amplified by a frequency and phase sensitive lock-in amplifier tuned to the precipitator modulation frequency. The resulting output signal gives a continuous measure of the sulfur particle concentration entering the instrument. Because this system is designed to have its electrical power turned off half of the time, it is clearly designed for detection, not protection of building""s occupants.
U.S. Pat. No. 5,938,823 to David A. Condit, Timothy N. Obee, Willard H. Sutton, Richard R. Grzybowski, Christopher M. Pater, Antonio Rinaldi, Sunita Satyapal, Wayde R. Schmidt, Charles R. Winston, and Michael Winter, assigned to Carrier Corporation, filed Apr. 18,1997, and issued Aug. 17, 1999, describes an air cleansing apparatus including an electrostatic precipitator in which the collector plates are made of, for instance, reticulated chemical vapor deposited silicon carbide, or reticulated silicon carbide ceramic coated with titanium nitride, zirconium diboride, or chemical vapor deposited silicon carbide. Microorganisms entrained on the collector plates are thermally degraded or vaporized by microwave radiation directed against the plates during a sterilization period which follows a collection period.
The present invention provides an autonomous chemical and pathogen detection and remediation system. It provides a system for the detection and treatment of unwanted agents within the air inside of an enclosed airspace that is a gathering area for people. The air is channeled into an air stream. A detector system is located within the air stream for detecting the unwanted agents. An electrostatic precipitator and/or xe2x80x9cscrubberxe2x80x9d is connected to the air stream. A circulation system is provided for moving air within the air stream. A control is connected to the detector, the circulation system, and the electrostatic precipitator/scrubber to activate the electrostatic precipitator/scrubber in response to detection of unwanted agents.
This system can be used to monitor and remediate circulating air inside of an enclosed airspace. Specific examples of areas that need protection are subways, airports, entertainment centers, religious centers, office complexes, convention centers, and other sites where the public is at high risk of exposure to a covert release of biological or chemical agents. The system could be used for the detection and treatment of chemical and biological agents in the event a terrorist were to release an aerosolized agent into the airspace or the ventilation system. The present invention provides a prophylactic approach that can avoid many of the problems of the prior art by providing remediation of the entire air supply.
Implementation of the present invention would have a deterrent effect. The complete vulnerability of public areas such as subways, airports, entertainment centers, religious centers, office complexes, convention centers to terrorism prompt other terrorists to attempt the same type of attack for extortion or additional terror impact. The existence of the building protection system of the present invention would provide a deterrent to this type of extortion.
Another important use of the building protection system is that it can be used to provide a safe haven in the event of a terrorist BW attack. A BW agent terrorist attack could be dealt with to some degree, if buildings is equipped with the system described and claimed in this patent application. People would be advise to stay inside the building, equipped with the system described and claimed in this patent application, while the cloud of BW agent dispersed. The occupants of the building would be protected until the main cloud of BW agent passed.
There are other uses of the present invention. Air monitoring is of critical importance to public health assessment. There needs to be a system capable of providing a warning of a high level of airborne particulates and treatment of the dangerous particulates. For example, recirculation of air in buildings as indoor pollution causes worker illness. Unwanted particles accumulate in the recirculated air. Nosocomial, or hospital-acquired infections are often caused by antibiotic resistant microorganisms spread throughout the hospital in air-handling systems. The infections are also in the ambient air caused by movement between rooms by hospital personnel. The present invention provides an autonomous chemical and pathogen detection and remediation system that will diminish or eliminate these problems.
Additional aspects, advantages, and features of the invention are set forth in part in the following description. Various aspects, advantages, and features of the invention will become apparent to those skilled in the art upon examination of the description and by practice of the invention.